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(BASIC) D–Vac Sample Report: Sanders May 23


Deke Letter to Sanders

May 23, 2001

Dear Roger,

Last week (5/17), Francisco and I sampled the various habitats around your fields using ‘the D–Vac’, an insect vacuum net. The advantage that the D–Vac has over the sweep net is its ability to collect small insects like parasitic wasps. These insects can be a major mortality factor for their target host (usually your pest). Also, the D–Vac typically collects a greater diversity of insects than a sweep net thus it allows the sampler to better decide whether the pests in the sample is likely to become a pest or not based on the other insects in the sample. Insects typically considered pests are listed at the top of the list for each location.

Below are rough inventories of the number and types of insects collected at each habitat location. The approximate number of seconds that each location was sampled are next to each location so that a rough comparison between locations can be made. In general, although pests were present in every sample, the number of beneficials present usually exceeded the number of pests. These beneficials are your standing army protecting your cotton from an invasion of these pests. Hopefully this inventory will give you some idea of the diversity of beneficials available in your surrounding habitat.

S. Bakersfield alfalfa – sampled 100 sec.––near your field

2 cabbage loopers

8 Say stink bug

4 Lygus adults

1 false chinch bug

6 Blood Red Ladybeetles

1 Convergent ladybeetle

2 damsel bugs

25 big–eyed bugs

many assorted parasitic wasps; attack worms and aphidsp

2 collops beetles

8 hooded beetles

several leafhoppers

assorted crab spiders


As you can see, your alfalfa field harbors a tremendous number and diversity of ladybeetles, big–eyed bugs, beetles and parasitic wasps. Also, note how few Lygus adults and the lack of nymphs were present in this sample. This is a good indication that the beneficials are eliminating most of the immature stages.


S. Bakersfield wheat–sampled 60 sec.

18 Say stink bug

2 cucumber beetles

~25 Lygus adults,~100 Lygus nymphs

1 Convergent ladybeetle adults

2 Convergent ladybeetle larvae

4 assassin bugs; 3 Zelus, 1 Sineid

2 damsel bug

28 big–eyed bug

several leafhoppers

1 collops beetle

assorted crab spiders


N. Bakersfield alfalfa–sampled 100 sec.

6 yellow striped armyworms

2 Lygus adults

8 Say stink bugs

1 false chinch bug

10 Convergent ladybeetle adults

2 blood–red ladybeetles

5 big–eyed bugs

2 Syrphid flies

8 hooded beetles

2 Collops beetles

5 minute pirate bugs

2 green lacewing adults

several assoerted parasitic wasps

serveral western flower thrips

assorted crab spiders


N. Bakersfield trees and corn

3 Say stink bug adults, ~15 Say stink bug nymphs

3 Lygus adults, 25 Lyugus nymphs

4 blood–red ladybeetles

2 Sineid assasin bugs

4 damsel bugs

30 big–eyed bugs

assorted leafhopper and crab spiders


E. Bakersfield grass and weeds – sampled 50 sec.

3 Say stink bugs

1 blood–red ladybeetles

19 hooded beetles

2 assassin bug nymphs

many assorted parasitic wasps

2 flower flies

assorted leafhoppers

7 big–eyed bug adults


Safflower –sampled 50 sec.

10 yellow striped armyworms

5 beetle larvae

4 Lygus adults

~100 western flower thrips

7 minute pirate bug

10 hooded beetles

7 big–eyed bug adults, 5 big–eyed bug nymphs

2 flower flies

5 green lacewing adults

assorted leafhoppers

several assorted parasitic wasps


AG cotton – sampled 50 sec.

3 cabbage loopers

3 Lygus adults, 10 Lygus nymphs

2 green lacewing adults

2 minute pirate bugs

8 big–eyed bug adults

few leafhoppers


Slight leaf damage seen in southwest corner of field on 5/10. Plants outgrew most of damage when sampled on 5/17.

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