[MAIPC] SLF Research Questions and Summation October 25, 2018

[Richard Gardner]

SLF Research Questions and Summation  October 25, 2018

Richard Gardner 

Berks County, PA

Questions

1.      Ailanthusaltissima is obviously the favorite SLF food. However, it apparently usesmany other woody plants as food sources. Are these plants such as wild grapetoxic to the SLF in the same way many foods human consume are toxic yet stillconsumed? Human examples are the relationship between high fructose corn syrupand diabetes 2 or ethanol, liver cirrhosis and ethanol poisoning. Dogs and catsdrink ethylene glycol and become very ill because of it.

 

2.      Why am I seeing few egg masses compared to thenumber of adult SLF?

a.      A skewed gender ratio with more males thanfemales?

b.      A few queens with the rest of the females beingnon-breeders?

c.      Is there a high number of sterile/infertilemales/females?

d.      Are infertile males impregnating females,causing infertile eggs?

e.      Am I missing the breeding timing either becausethe egg laying timing is later than I expect, or eggs need time to incubateinside the female before being laid?

 

3.      Is Ailanthusaltissima necessary for survival and/or reproduction?

 

4.      What is the hierarchy of foods? Ailanthus altissima is obviously the topfood with apparently wild grape being the second.

 

5.      Are the three size classes I am seeing due toage, gender or both?

 

6.      Do the smallest size adults overwinter?

 

7.      What causes breeding and egg deposition?

a.      Days from start of adulthood?

b.      Environmental conditions such as day length orair temperature?

 

8.      At what air temperature does SLF die?

 

9.      What caused the explosive growth of the SLFoutbreak?

a.      Two exceptionally wet summers?

b.      The end of the lag time and movement to log growthon the Gaussian curve as a normal part of invasions regardless of weather conditions?

 

What I know

1.      There appears to be a large difference in SLFbehavior between urban/suburban and rural locations. I do most of my researchin a rural ecology which is a mixture of forests, fields maintained forwildlife and agriculture. Therefore, my data will have some distinctdifferences with urban/suburban ecologies.

2.      Ailanthusaltissima is the preferred food with wild grapes apparently being second,followed by other vines and trees.

3.      Size of the trunk/vine diameter matters. Small Ailanthus clones and free-standing treeshave no SLF on them. The same applies in a lesser degree to wild grape andpossibly Oriental bittersweet, Celastrusorbiculatus.

4.      I am seeing at least 3 distinct sizes of SLFwith the largest apparently being gravid females, but with some apparentlymales being in the largest size class.

5.      Eggs appear to be laid then a protectivecement-like coating applied.

6.      There are very few egg masses in relationship tonumber of adults.

7.      SLF has a high tolerance to lower temperatures,a huge competitive advantage.

8.      Egg laying is somewhat food surface oriented.However, some of the egg laying appears to be random on non-food surfaces suchas birch trees, box elder and pignut hickory. This may help explain the spreadof SLF because it sometimes lays eggs on random surfaces which get transportedelsewhere.

9.      There appears to be wasps, bees, yellow jackets,flies and fruit flies tapping the sap wounds from SLF and possibly the waste ofSLF.

10.  At the present time, the largest clusters of SLFare at the base of Ailanthus trees.

11.  Wild grape has a few SLF clustering together, usuallyat most 4 or 5 individuals, as opposed to the clusters of 30+ often found on Ailanthus. This may be due to vinediameter.

12.  Apparently, nymphs hide in foliage regardless ofthe size of the Ailanthus tree.Adults are found in plain sight on the trunks of trees and vines. This lack ofpredator avoidance may be like Attevaaurea which has no defensive flight patterns when flying. My assumption isthat this is due to the obnoxious chemicals it consumed from Ailanthus as larvae. This is similar tomonarch butterflies and milkweed.

13.  The PA Game Commission is a primary factor forthe spread of SLF, in addition to other non-natives, because they do not washtheir vehicles between the locations they do work.
14.  Be wary of type 1 and type 2 errors. An SLFresting on a plant is very different than feeding or depositing eggs on one.
PHOTOS POSTED AT https://www.facebook.com/Ailanthusresearch/ .
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