water beetle pic

[Galapoheros]

Anybody know about the chems in the milky defensive fluid that oozes from around their head?, strange smell.

 

[beetleman]

:drool: ooh! awesome diving beetle! yeah i'm not really sure about the defensive fluid,what i do know it's toxic in the water to other animals,even each other if they stress out too much,and ofcourse they proberly would'nt taste good to a predator trying to eat them.

 

[Widowman10]

i did a quick google search on the chemical secreted and came up with nothing. i would be interested to hear what exactly it is.

 

[spydrhunter1]

http://www.colostate.edu/Depts/Entomology/courses/en570/papers_1996/miller.html

 

[Widowman10]

http://www.colostate.edu/Depts/Entomology/courses/en570/papers_1996/miller.html

wow! thanks for the excellent link!! :clap:

All Adephaga deliver compounds
in one of three ways depending on taxon. These are

1) oozing,
2) spraying and
3) crepitation.

While many compounds have unknown functions, it is suspected that most compounds
have one or more of six possible functions,

1) defense against vertebrate predators,
2) facilitation of penetration of defense compounds into predator integuments,
3) antimicrobial and antifungal (especially in Hydradephaga),
4) increasing wetability of the integument (Hydradephaga),
5) as alarm substances,
6) as a propellant (Gyrinidae), and
7) conditioning of plant tissues associated with oviposition.

cool stuff

also very good:

The coleopteran suborder Adephaga contains eight families, all of which secrete a
variety of glandular substances. All families possess paired pygidial glands
located postero-dorsally in the abdomen. These glands open onto the eighth
abdominal tergum. Additionally, the families Dytiscidae and Hygrobiidae possess
paired prothoracic glands. The prothoracic glands of Dytiscidae secrete a variety
of steroids, some of which are identical to typical vertebrate steroids, a
phenomenon unique among Arthropoda. The most widespread dytiscid steroid is
deoxycorticosterone. Pygidial glands are relatively uniform in structure throughout
the suborder but vary in chemical constituents. Dytiscidae, Gyrinidae and Carabidae
are the families most studied. Gyrinids produce unique norsesquiterpenes. These
are gyrinidal, isogyrinidal, gyrinidone and gyrinidione. The most common pygidial
gland compounds in Dytiscidae are aromatic aldehydes (e.g. p-hydroxybenzaldehyde),
esters (e.g. methyl p-hydroxybenzoate) and acids (e.g. benzoic acid). Dytiscids
also produce many less widespread and/or more rare compounds. Carabids also produce
a diverse array of pygidial chemicals. These are generally hydrocarbons, aliphatic
ketones, saturated esters, formic acid, higher saturated acids, unsaturated
aliphatic acids, phenols, aromatic aldehydes or quinones. The most characteristic
compounds are carboxylic acids, particularly formic acid, methacrylic acid and
tiglic acid. Among the more interesting compounds produced by carabids are 1,4
quinones and hydroquinones ejected explosively by members of Brachinini.

now, what family or even genus is this guy in??

 

[spydrhunter1]

I think you have yourself a member of the Family Dytiscidae.
http://www.anbg.gov.au/cpbr/WfHC/Dytiscidae/index.html

 

[Galapoheros]

That was an awesome dig! Chemical warfare is alive and well!

 

[beetleman]

wow! that is some awesome news about their chemicals,also it could be cybister sp. aswell texas has alot of sp.

 

[dtknow]

I didn't read, but is the chemicals for defence or perhaps waterproofing the beetle?

 

[Galapoheros]

It mentioned both I think, something about "wetability", some other theories too, maybe some things we dtknow yet.