BIO BUZZ ISSUE 27 October A GROWERS REFERENCE TO BIOLOGICALS Pesticides And Whitefly: From the Bugs How Can I Tell If Theyʼre Dead? Eye View… Evaluation of IPM methods has always been part of our Biological Have a look at some of the insects and Scouting Service. Part of evaluation is to check on the percent kill in the greenhouse and you’ll ﬁnd after a pesticide application. Cleanup of whiteﬂies has already started at some interesting fungi that are some farms; heavy pressure from outside over the past few weeks has naturally occurring, but are not overwhelmed some Biological programs and before any honeydew considered diseases; at least of plants starts there is going to be some spraying. anyway. They are Entomopathogenic The adult whiteﬂy is mobile, so it’s obvious what to look for after a fungi, or Insect-pathogenic. They feed pesticide application – a carcass. The ﬁrst instar larva is semi-mobile and on various components of the insect can be ﬂipped over on their backs body and are spread mechanically to see if the legs are still moving. from insect to insect. They are Note that it takes a steady hand commercially available in other and 40x magniﬁcation to try this. countries (ex Beauvaria bassiana) for Or you can wait and see if it Dead insect control. They are usually shrivels up in a few days. Some prevalent when there is consistently of the larger larvae will turn a high humidity and a low incidence of brownish colour as well as Alive fungicide sprays. shrivel up. Alive vs. Dead Whiteﬂies Pest Alert: Diapausing Spider Mites As of September 16, 2005, orange coloured two-spotted spider mites have been sited at a cucumber greenhouse. Since then, there have been a few more noticed, but the percentage is still low as of the last week of September. The percent of adult females that will go into diapause will continue to increase as the daylength shortens. We suggest that now is the time to clean up mites to prevent overwintering and early problems next year. Note that once mites have found shelter for overwintering, it’s almost impossible to eliminate them with chemical means. Another Way We Are Helping You Grow Fungal Pathogen On An Insect 50 Hazelton St., Leamington, ON, N8H 3W1 519-326-9037 Out And About In Southwestern Ontario All Crops: • Cabbage looper moths are still in abundance. The inﬂux from outside should slow now that the vents are not open continuously. Eggs and larvae are still a concern. • Spider mites have started to go into diapause. Tomatoes: • Heavy whiteﬂy pressure from outside has led to abundant larvae and hot spots starting despite very eﬀective biological programs. • Russet mites have increased signiﬁcantly at some farms. This is mainly due to mites that have spread to new plants and are now showing damage. • Bacterial canker continues to spread. Even though it’s near the end of the growing season, it’s still important to remove infected plants. • Pepino Mosaic Virus continues to show up at more farms. Yellow spots, mosaic patterns on leaves and some “bleached” calyxes are more evident as the daylength decreases. • Aphids in small numbers are present. • Another round of powdery mildew has started at some farms. Cucumbers: • Cucumber Mosaic Virus (CMV) and other viruses continue to be detected, especially as picking starts. This goes hand in hand with the increase in detection of new Melon aphid populations and mechanical transmission of existing infected plants. Any plants showing fruit with viral symptoms should be removed. • Cucumber beetles, both spotted and striped, are present in limited numbers. Note they can spread Bacterial Wilt and CMV. • Downy mildew has again been detected at quite a few farms. Wet, cold conditions are perfect for infection and establishment. Peppers: Downy Mildew On A Cucumber Plant • Powdery mildew has been detected at a few farms. • Generally, thrips have been under control due to high populations of Degenerans and a new surge of Cucumeris in the past month. • Broad mites have continued to do some limited damage to fruit at almost all pepper greenhouses. Workers should try to avoid touching plants with symptoms as the mites can be spread on clothes and hands. Note that the new population increase of Cucumeris has helped with the Broad mites. We are ﬁnding good numbers of Cucumeris under the calyx feeding on Broad mites. Unfortunately the damage inﬂicted by just a few Broad mites (i.e. scabbing of the shoulder) can prevent marketability of the fruit. The Ever Present Chickweed Everyone has it; everyone tries to get rid of it; everyone pays for it. This common little weed may start out small, but it can become a tangled mess of vine-like growth. Chickweed (Stellaria sp.) can reproduce by seeds and by sending out roots at nodes. It’s quite a marvel of science. It’s also costing you money. Chickweed is host for major insect pests (Lygus, spider mites, whiteﬂy, thrips, and aphids) and diseases like Cucumber Mosaic Virus (CMV), Impatiens Necrotic Spot Virus (INSV) and Tomato Spotted Wilt Virus (TSWV)1. Cleanup should include pulling of all weeds now. Diligence is certainly needed for this one in particular. 1 PEI Agriculture, Fisheries, and Aquaculture Government Chickweed Publication 1400A; BC Ministry of Agriculture, Food and Fisheries website.
Pages to are hidden for
"Pesticides And Whitefly How Can I Tell If Theyʼre Dead Pest "Please download to view full document