USING RANDOM SAMPLING TO ESTIMATE INSECT COUNTS AS RESPONSE SURFACES INVOLVING SPACE AND TIME

In fall 2000, an on-farm sustainable agricultural research project was established for cotton (Gossypium hirstum L.) in Tift County, Georgia. Twenty fields that were to be planted to cotton in 2001 were identified which were approximately 5 to 10 acres in size. Four randomly selected fields were assigned to each of five cover crops: 1) cereal rye (Secale cereale L.); 2) crimson clover (Trifolium incarnatum L.); 3) legume mixture of balansa clover (T. michelianum Savi), crimson clover, and hairy vetch (Vicia villosa Roth); 4) previous legume mixture plus cereal rye; and 5) no cover crop (fallow) in conventionally tilled fields. Cotton was planted in two rows (36 in apart) on six foot beds. A strip was burned out in each row in the four cover treatments using paraquat so cotton could be planted. In the spring, insect counts were determined using sweep nets in the covers and when the cotton was small. Cotton plants from emergence to four weeks old were not sampled since the sweep net could break the fragile cotton plants. Five more weeks of sweep net data were collected from cotton. Insect samples after this involved whole plants since the cotton was too big for the sweep net to be effective. Each field was divided into 24 x 24 foot sample areas beginning at the center of the field. Each week for 14 or 15 weeks, 21 samples were obtained from each field. Comprising the 21 random samples were one sample from the four center plots, one sample from each of the four sides, and four samples from each of the four quadrants. Thus throughout the season, a five acre field could have most of the plots sampled at least once. Larger fields saw a smaller percentage of all the plots sampled. No interior plot excluding the center and edges was sampled a second time until every plot had been sampled once. A response surface was fitted for the weekly data for each field. As would be expected, high densities of insects resulted in a significant fit

New record of Trissolcus solocis (Hymenoptera: Scelionidae) parasitising Halyomorpha halys (Hemiptera: Pentatomidae) in the United States of America

A parasitoid wasp, Trissolcus solocis Johnson, was recorded parasitising eggs of the invasive stink bug Halyomorpha halys (Stål), in the United States. This is the first record of this species parasitising eggs of H. halys. First record of Trissolcus solocis parasitising Halyomorpha halys eggs in the United States and first record of T. solocis in Alabama

Ecosystem-Based Incorporation of Nectar-Producing Plants for Stink Bug Parasitoids

Adult parasitoids of pest insects rely on floral resources for survival and reproduction, but can be food-deprived in intensively managed agricultural systems lacking these resources. Stink bugs are serious pests for crops in southwest Georgia. Provisioning nectar-producing plants for parasitoids of stink bugs potentially can enhance biocontrol of these pests. Knowledge of spatial and temporal availability and distribution of stink bugs in host plants is necessary for appropriate timing and placement of flowering plants in agroecosystems. Stink bugs move between closely associated host plants throughout the growing season in response to deteriorating suitability of their host plants. In peanut-cotton farmscapes, stink bugs develop in peanut, and subsequently the adults disperse into adjacent cotton. Parasitism of Nezara viridula (L.) adults by Trichopoda pennipes (F.) at the peanut-cotton interface was significantly higher in cotton with a strip of milkweed or buckwheat between the two crops than in cotton alone. Milkweed and buckwheat also provided nectar to a wide range of insect pollinators. Monarch butterflies fed on milkweed. When placed between peanut and cotton, a strip of soybean was an effective trap crop for cotton, reducing economic damage. Incorporation of buckwheat near soybean enhanced parasitism of Euschistus servus (Say) eggs by Telenomus podisi Ashmead in cotton. In conclusion, nectar provision enhances biocontrol of stink bugs, acts together with other management tactics for stink bug control, and aids in conservation of natural enemies, insect pollinators, and the monarch butterfly

Reproductive Morphology, Histology, and Gametogenesis in \u3cem\u3eOrnithodoros parkeri\u3c/em\u3e (Cooley) (Acarina: Argasidae)

Adult males recently ecdysed from second, third, or fourth instar nymphs had a complete reproductive system which included paired testes, paired vasa deferentia, a single seminal vesicle, a single ejaculatory duct, and an accessory gland with 2 single and 8 paired lobes. Each accessory gland lobe was composed of one type of tissue, spongy or granular. Probable secretory flow in these lobes was outlined. Cytological descriptions of spermatogenesis were similar to those reported for other tick species. Primary spermatocytes, under-going the first meiotic division, possessed 9 autosomal bivalents and 1 sex bivalent, 2n=2G. Spermatogenesis was complete in a few unfed fifth instar nymphs examined and in all unfed-unmated adult males examined. Unfed-unmated adult males 2 weeks post-ecdysis could mate with fed adult females which would subsequently lay viable eggs. The female reproductive system of fourth instar nymphs (which could ecdyse into adult females) was complete, except for absence of paired ampullae, and included a single ovary, paired oviducts, a single uterus, a vagina, and paired accessory glands. Primary oocyte development was divided into 5 growth phases. Meiotic divisions of oocytes were not observed. Accumulation of sperm in ampulla of adult females, absence of sperm in the ovary and proximal portions of the oviducts, and apparent decreased pliability of eggs after passing through ampullae indicated that fertilization may occur in the ampullae