a friend of mine had his giant pumpkin totally desimated in one day by a maggot infestation you can see it here
http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=162883
sorry about pic quality we got a sample and sent it off to the RHS for identification here is the results
Ref: 13962403/173107
Thank you for your enquiry to the Royal Horticultural Society's Members' Advisory Service.
Thank you for sending some samples of the larvae that are attacking your pumpkins. They are larvae of a bibionid fly (Bibio sp.). This type of fly maggot is not uisually a problem on pumpkins as they niormally feed on decaying plant material in the soil. They can sometimes be found together in large numbers where there are accumulations of dead leaves. I suspect in this case the larvae may have been introduced with the cow manure or other organic manures applied to the growing site. The tissues on young pumpkin plants are relatively soft and might not provide much of an obstacle to prevent these larvae entering the plant stems and fruits.
As this is an exceptional form of damage, it may not happen again in future years. Control of the larvae will not be easy as larvae that live in the soil or have bored into plants are difficult to get at. There is the added problem in a vegetable garden of finding a suitable pesticide that is approved for use on the particular type of vegetable. Next year it would be advisable not to apply the cow manure that may have introduced the larvae. Any larvae that survive the insecticide treatment you have applied are likely to become adult flies next spring. They may lay eggs on your allotment site but hopefully, this problem will not repeat itself next year.
Yours sincerely
Andrew Halstead
Principal Entomologist
Well?..was there cow or other manure applied close by?
yes there was a large amount of manured added to a new plot he had just taken over it was from a local farmer we all buy it from its cow manure from his over wintering of stock in barns
the rhs said also over the phone that its was new new one for them to have fruit and vines of pumpkins attacked by these flies maggot they usually only damage grassland and eat dacaying matter
Oh dear! Doesn't look good at all, and thanks for letting us know about this. I'm using cow manure on my plot this year, I normally have horse manure. I had a real problem last year with squishy squash - http://www.allotments4all.co.uk/smf/index.php/topic,62486.0.html - so I'm kind of on the alert to problems with diseases etc. Do you think it is just affecting the Giants? Also it didn't occur to me to contact the RHS, good idea
:)