Trade-offs and synergies in management of two co-occurring specialist squash pests

Journal of Pest Science - Co-occurring herbivorous pests may have shared or divergent responses to plant- and insect- derived cues, creating challenges for effective pest management in...     

Simultaneous determination of (45)calcium and (65)zinc uptake by caco-2 cells

A simple method for simultaneously determining cell-associated Ca and Zn in Caco-2 cells is described. Calcium and zinc uptake was measured via radioisotopes (45)Ca and (65)Zn. Preliminary studies revealed that (65)Zn, a positron (beta(+)) and gamma emitter, contributed to (45)Ca counts in a liquid scintillation counter (LSC). However, (45)Ca, being a true beta emitter, did not contribute to the counts in a gamma counter (gammaC). To differentiate the counts of (45)Ca from those of (65)Zn, first a (65)Zn-labeled cell suspension was read in a gammaC and an LSC, thus obtaining the relationship between the radioactive counts obtained from the gammaC and LSC. This information defined the linear relationship between gammaC (65)Zn counts per minute (CPM) and LSC (65)Zn CPM. Because the (45)Ca and (65)Zn counts obtained in the LSC are additive, giving total LSC CPM, the value of LSC (45)Ca CPM was obtained by subtracting LSC (65)Zn CPM from total LSC CPM for the dual-labeled cell sample, obtaining then LSC (45)Ca CPM. To determine the absolute activity or disintegrations per minute (DPM) of each isotope in the dual-labeled sample, the linear relationship between DPM and CPM was determined for each isotope. The method is simple and straightforward for the determination of (45)Ca counts from a sample also containing (65)Zn, using gamma and liquid scintillation counters.     

Slowing the Spread of Grapevine Leafroll-Associated Viruses in Commercial Vineyards With Insecticide Control of the Vector,Pseudococcus maritimus (Hemiptera: Pseudococcidae)

Vineyards were surveyed for grapevine leafroll-associated viruses and their insect vectors in New York State’s Finger Lakes region in 2006–2008. Grape mealybug, Pseudococcus maritimus (Erhorn) (Hemiptera: Pseudococcidae), European Fruit Lecanium, Parthenolecanium corni (Bouche), and Cottony Maple Scale, Pulvinaria acericola (Walsh and Riley) (Hemiptera: Coccidae) were identified as vector species in this region. An increase in the incidence of Grapevine leafroll-associated virus 1 (GLRaV-1) and GLRaV-3 was observed in 8 of the 20 vineyards surveyed, which implies transmission by these insect vectors. Two of the vineyards for which a temporal increase in disease incidence was documented were then used to evaluate the efficacy of foliar applications of horticultural oil and two classes of insecticides for control of P. maritimus and for slowing virus spread over 2 years of vine protection. Delayed dormant applications of horticultural oil contributed to control of early season crawlers; however, this was not the case for control of summer populations. Applications of acetamiprid and spirotetramat achieved control in summer populations; however, spirotetramat outperformed acetamiprid in percent reduction of treated compared with control vines and in a side-by-side trial. Vines treated with spirotetramat had a lower percentage of new vines testing positive for GLRaV-1 than control vines after 2 years, while no other spray program altered the increase in incidence of GLRaV-1 or -3.