Killed Virginia pine, (Pinus virginiana Mill.), held in the vertical position, attracted 99.65 percent of the insects in the families Scolytidae, Cerambycidae, Curculionidae, and Buprestidae. The remaining 0.35 percent were collected from nontreated control trees. The dominant insect species were analyzed regarding seasonal abundance and specificity in selecting suitable host material. / Master of Science

Coconut mite populations and levels of damage to 2-, 4- and 10-month old Maypan and Red Malayan Dwarf nuts in Low and High Rainfall Zones of eastern Jamaica were evaluated. Damage due to the coconut mite was assessed by quantifying scarring of the nut surface, size reduction and copra yield. It was found that coconut mite populations were the same in the two rainfall zones but differed between Maypan and Red Malayan Dwarf varieties. More Maypan nuts were infested with coconut mites than Red Malayan Dwarf nuts. More 2-month old Red Malayan Dwarf nuts were attacked than 2-month old Maypan nuts while more 10-month old Maypan nuts were colonized than 10-month old Red Malayan Dwarf nuts. In both varieties, a greater percentage of 4-month old nuts had > 1,000 coconut mites than 2- and 10-month old nuts. Nuts in the Low Rainfall Zone had greater percentage of coconut mite damage than nuts in the High Rainfall Zone. Damage was more severe on Red Malayan Dwarf than on the Maypan nuts. The water content of Red Malayan Dwarf nuts declined with increased coconut mite damage but no relationship was found between the water content of Maypan nuts and coconut mite damage. Nut size and copra yield declined significantly with increased coconut mite damage. Total copra yield loss was only about 3% in Maypan and 6% in Red Malayan Dwarf nuts because most of the nuts had < 30% surface area damage. / Master of Science

Thesis (M.Sc. (Agricultural Agronomy)) --University of Limpopo, 2015 / Refer to document / Department of Agriculture Forestry and Fisheries (DAFF)

The relevance of the study. Apple sawfly (Hoplocampa testudinea Klug), black plum (Hoplocampa minuta Christ.) and yellow plum (Hoplocampa flava L.) sawflies (Hymenoptera, Symphyta, Tenthredinidae) are serious and widespread pests of apple and plum fruits. Dock sawfly (Ametastegia glabrata Fall.) is a non-specialized apple pest and its larvae feed generally on leaves of Chenopodium sp. and Polygonum sp.; however, occasionally mature fruits at harvest are found damaged by larvae of this insect. Former studies indicated that these species caused significant damage to apple and plum yield in Lithuania in mid-late XX century. However, at that time the setup of apple and plum genotypes cultivated was completely different from conventional orchard management techniques and cultivars at present time. Therefore, the growing diversity of cultivated fruit-tree genotypes leaves gaps in knowledge as to how apple and plum sawflies will affect some of the newer cultivars. In Lithuania, no data on susceptibility of economically important apple and plum cultivars to sawfly damage in commercial orchards is available. A shift towards integrated pest management and development of organic fruit farming poses new challenges to apple growers and plant protection specialists. According to the requirements of these management strategies, the use of synthetic pesticides must be reduced or is not allowed at all. Several reports from countries where the use of synthetic insecticides was significantly... [to full text] / Temos aktualumas. Obuolinis pjūklelis (Hoplocampa testudinea Klug), slyvinis juodasis (Hoplocampa minuta Christ.) ir slyvinis geltonasis (Hoplocampa flava L.) pjūkleliai, priklausantys plėviasparnių (Hymenoptera) būriui, tikrųjų pjūklelių (Tenthredinidae) šeimai, yra reikšmingi specializuoti obelų ir slyvų vaisių kenkėjai, paplitę viso pasaulio obelų ir slyvų auginimo regionuose (Velbinger, 1939; Alford, 2007; Vincent, Belair, 1992). Rūgtinis pjūklelis (Ametastegia glabrata Fall.) priklauso tai pačiai šeimai – ir, nors jo lervos pagrindinai minta balandinių ir rūgtinių augalų lapais, tačiau dažnai aptinkama ir šio vabzdžio lervų pažeistų obuolių. Anksčiau Lietuvoje obuolinis bei slyviniai pjūkleliai būdavo žalingi senesniuose soduose. Susidarius palankioms sąlygoms masiškai plisti arba vaismedžiams derant negausiai, šių kenkėjų daroma žala viršydavo kitų pagrindinių obelų ir slyvų kenkėjų, tokių kaip obuolinis (Cydia pomonella L.) ar slyvinis (Grapholita funebrana Treits) vaisėdžiai, daromą žalą. Pavyzdžiui, slyviniai pjūkleliai susidarius palankioms sąlygoms – šiltam ir ankstyvam pavasariui, sunaikindavo daugiau kaip 60% kai kurių veislių slyvų vaisių derliaus (Заянчкаускас, 1958). Per paskutinius du dešimtmečius Lietuvoje senuosius sodus pakeitė intensyvūs ir ekologiniai sodai, kuriuose sodinami naujų veislių vaismedžiai su žemaūgiais poskiepiais. Pasikeitus ūkininkavimo sąlygoms, keičiantis aplinkos sąlygoms, šylant klimatui, keičiasi kenkėjų rūšinė sudėtis bei žalingumas... [toliau žr. visą tekstą]

The infestation of twelve selected clones of alfalfa by the alfalfa seed chalcid was measured. The free sterol content of the stems, leaves, f lowers and pods of these clones was determined. A check was made to see if there was a correlation between the sterol content and the chalcid infestation. Differences were found among t he clones in the sterol content for each plant part. There were also significant differences in percent chalcid infestation in the 12 clones. Duncan ' s New Multiple Range Test pointed out which clones differed Significantly from the others. Using linear regression analysis, the correlation coefficient of the comparison between the sterol content and the chalcid infestation was obtained. There was a signtflcant negative correlation between the sterol content of the flower and the percent chalcid infestation. No significant correlation was found between t he sterol content of the stems, leaves or pods and the percent chalcid infestation.

One of the limiting factors associated with seed production of alfalfa and certain clovers is a small jet-black wasp commonly known as the clover seed chalcid, Bruchophagus gibbus (Boheman). In alfalfa seed producing areas this insect is often referred to as the alfalfa seed chalcid or the alfalfa seed chalcis-fly. In local areas of Utah, farmers often refer to this insect as simply "the fly."

The work presented in this thesis is concerned with the chemotherapy of parasite infestations in the ruminant with the anthelmintic thiophanate [diethyl 4,4'-o-phenylene bis (3-thioallophanate)]. A new concept of administration was investigated, namely continuous low-level anthelmintic medication. Two aspects were studied which divide conveniently into two sections. In Section 1, following preliminary trials undertaken to assess the low-level anthelmintic activity of thiophanate, the effects are assessed when this drug is administered continually directly into the rumen of parasitised sheep. Thiophanate was infused at dosages between 3.0 and 5.0 mg per kg bodyweight over various periods of medication against various developmental stages of gastro-intestinal parasites. The daily drug release rate. required to inhibit egg hatch and eliminate the worm burden is established. A minimum daily release rate of 3.0 mg per kg bodyweight was shown to be required to completely inhibit egg hatch and 4.5 mg per kg for effective vermicidal activity. In similar experiments, the anthelmintic activities of levamisole (s-(-)-2,3,5,6-tetrahydro-6-phenylimidazo (2,1-b) thiazole), febantel (N-(2-(2,3-bis-(methoxycarbonyl)-guanidino)-5-(phenyl-thio)-phenyl)-2-methoxy-acetamide) and briefly oxfendazole (5-(phenylsulfinyl)-IH-benzimidazol-2yl) carbamate) were also examined. In Section 2, the development of an intra-ruminal bolus incorporating thiophanate and designed to release drug at a predetermined rate over an extended period of time is described. Experiments were carried out in sheep to assess the bolus density required for retention within the reticulo-rumen (monitored by direct bolus recovery), to compare various density factors (iron powder, iron bar core, iron shot and sand) and to assess the average drug release rate from different matrix formulations (based on fatty acids, palmitic acid and paraffin wax) when the boluses were dosed singly or in pairs. The development of a stable "carrier" on which to load a suitable matrix is also described, the majority of the experiments undertaken utilising this "carrier". The effect on the drug release rate of incorporating various "leaching aids" (digestible materials, wetting and soluble agents) into the matrix is examined and preliminary anthelmintic trials undertaken in experimentally infected lambs. The required drug release is achieved when the boluses are administered in pairs. The anthelmintic activity is confirmed. Possible matrices suitable for use as a single bolus administration were produced. The advantages of this form of anthelmintic medication over the single therapeutic dose are discussed along with some indications for further studies that emerged.

Doctor of Philosophy / Department of Grain Science and Industry / Subramanyam Bhadriraju / The lesser grain borer, Rhyzopertha dominica (F.), females lay eggs loosely outside of wheat kernels. Larvae hatching from eggs enter wheat kernels to complete immature development. Four laboratory experiments were conducted to understand the wheat kernel infestation by first instars of R. dominica at 28°C and 65% r.h. The first experiment compared different kernel to first instar ratios on sound hard red winter (HRW) wheat class, probability of successful infestation, and subsequent adult development as affected by site of feeding on the kernels. Infested kernels were dissected 21 d after infestation to determine stage of development and larval weight. Development of larvae to adulthood was monitored for 50 d from time of infestation. Different kernel to first instar ratios did not affect probability of infestation, entry site preferences, larval development and weight, and days to adult emergence. In the second experiment one first instar was placed with a kernel on each of seven different wheat classes. Wheat kernels were artificially-damaged with a microdrill at the germ, endosperm, and brush end, and the sound kernels served as the controls. At 21 d, 82-90% of artificially-damaged HRW wheat kernels were infested by larvae versus 12% for sound kernels. Five times fewer hard white (HW) wheat sound kernels were infested by larvae compared with infestation in soft white (SW) wheat kernels. Sound kernels of durum, soft red winter (SRW), hard red spring (HRS), and hard white spring (HWS) wheat classes were more resistant to larval infestation than artificially-damaged kernels. Majority of first instars preferred germ as the entry site on HRW, HWW, SRW, and HWS wheat classes. Germ entry promoted faster larval development, leading to heavier larvae, and higher kernel weight losses. Adult emergence was earlier by 3-7 d compared with other sites across all 6 wheat classes, except for SWW class, where adult emergence was nil at 50 d. In the third experiment, speed of larval development on artificially-drilled HRW wheat kernels on different kernel sites. Three-hundred kernels each were drilled near the germ, endosperm, and brush end, and one first instar was placed per kernel in a glass vial. Kernels from glass vials were dissected every 3 d for 30 d and larval head capsule was measured. Larval development was fastest on the germ, followed by endosperm, and brush end. In the fourth experiment short-term feeding by R. dominica adults on infestation by first instars on sound wheat kernels was determined. Two laboratory tests were conducted with single and grouped (10) kernels using either two adults or two first instars per kernel. Signs of feeding were monitored for 21 d in single kernels and 7 d in grouped kernels. There was a significant association between adult feeding and larval infestation responses in single and group kernel tests. In conclusion, understanding factors that contribute to first instar establishment in wheat kernels will have impacts in breeding varieties that could be resistant and designing grain-handling equipment to minimize grain damage to mitigate R. dominica infestation of wheat.

Thirteen white pine plots, ranging from 15-26 years of age and one tenth acre in size, were sampled in six counties of southwestern Virginia. The number of trees attacked by the white-pine weevil ranged from 3.5 percent to 98.6 percent with an average of 40.0 percent. The incidence of forking was found to be 4.1 percent of the trees weevi1ed. Enough trees in the dominant and co-dominant crOvffi categories were either free of weevil attacks or only attacked once that 250 to 300 trees are available for final harvest. Most of the weevil attacks occurred between 5 to 12 years of age. Analysis of Covariance for non-weevi1ed terminals and lateral lengths developed the following relationship for three age classes of terminals and laterals. / Master of Science

My research addressed pheromone lure design and the activity of the grape berry moth, Paralobesia viteana, flight and infestation across three years of study. In my lure evaluations, I found all commercial lures contained impurities and inconsistencies that have implications for management. First, sex pheromone concentration in lures affected both target and non-target attraction to traps, while the blend of sex pheromones impacted attraction to P. viteana. Second, over the duration of study, 54 vineyard blocks were sampled for the pest in and around cultivated wine grape in Virginia. The trapping studies indicated earliest and sustained emergence of the spring generation in sex pheromone traps placed in a wooded periphery. Later, moths were detected most often in the vineyard, which indicated that P. viteana emerged and aggregated in woods prior to flying and egg-laying in vineyards. My research supports use of woods and vineyard trap monitoring at both the height of 2 meters and in the periphery of respective environments. These conditions should improve grower efficiency when using trapping as a tool. Cluster infestation was assessed relative to vineyard growth stage and location in the vineyard. My results are in agreement with historical studies that suggest infestation is highest in the periphery of vineyards. However, I found that infestation peaked at veraison before falling somewhat around pre-harvest. This indicated that growers should manage this pest prior to veraison, perhaps as early as budbreak, to prevent the insect from reaching damaging levels when the crop is more susceptible to loss. Lastly, by combining field-based data collection with remote climate and landscape monitoring, growers can achieve a greater level of surveillance of P. viteana. A mash up of remote and vineyard-based data can provide substantive pertinent information for management at both local and regional scales. If one grower identifies moth emergence, then growers nearby potentially can use that same information to initiate models to monitor development of the moth population in their own vineyard. This research complements the notion that the more a community shares information, the broader its applicability becomes to neighbors. / Ph. D.