Week 29 – July 15-21

2012 MOSQUITO REPORT: WEEK 29

Report based on data collected from traps deployed the week of July 15, 2012 through July 21, 2012. Report prepared by Chan Suom, M.S., Dave Lawson, and Nate Boonisar.

1. CURRENT MOSQUITO ACTIVITY/TREND

CDC Light Traps:
Due to logistical difficulties, only half of our host-seeking traps were deployed this week. Of those traps set, there is still variation in host-seeking mosquito populations ranging from below to above average.

Gravid Traps:
This trapping interval indicates that the population abundance of gravid mosquitoes is extremely lower than average all throughout Norfolk County. Only Medfield indicated an increase, albeit the Ochlerotatus japonicus species.

 2. CURRENT PREDOMINANT SPECIES

CDC Light Traps:
The most predominant CDC trapped mosquitoes in Norfolk County this week were Coquillettidia perturbans once again, with populations higher than average in Foxborough (~600), Plainville, Walpole (~400), and Wrentham. Culiseta melanura populations seem to be increasing in Sharon and other towns and are indicative of an upcoming emergence in the coming weeks.

Gravid Traps:
Though their populations are low, Culex pipiens/restuans are the most predominant species in gravid traps throughout Norfolk County.

3. COMPARISON TO PREVIOUS SEASON

The mixed collections for host-seeking mosquitoes and really low abundance of gravid mosquitoes are either a factor of low abundance as the phenology would suggest, or a factor of weather as traps were set during thunderstorm and rain events this week. Overall, mosquito collections returned lower numbers than average. This week’s thunderstorm and rain events may produce a new emergence of flood-dependent mosquito species, of which we should encounter within 2 weeks.

4. WEATHER SUMMARY

The beginning of the week was hot and humid with well above normal temperatures. A strong but slow moving cold front brought much cooler and less humid air by the end of the week. The front was accompanied by strong to severe thunderstorms that produced heavy rain in the northern and eastern sections. Amounts were generally under ¼ inch in the southwest towns while most eastern areas received ½ to 1 ½ inches of rain. A band of training thunderstorms brought amounts of 1 ½ to as much as 2 inches across parts of Dover and Needham. No widespread river flooding occurred, however localized small stream flooding may have happened across Dover/Needham and some localized areas in the east. Given antecedent dry conditions, most areas probably did not experience significant water table rises as most of the rain went to replenishing soil moisture.

Total weekly rainfall: 0.28 inches (-0.40 in.)
Total Monthly rainfall: 0.63 inches (-1.44 in.)
Total Yearly rainfall: 15.59 inches (-7.75 in.)

5. NUMBER OF REQUESTS FOR SERVICE

NCMCD has received 4,702 calls year to date for services as of 7/20/12. The NCMCD received 686 calls for service this week.

6. MCP/COMMISSION RESPONSE

The NCMCD continues to respond to ULV requests by residents. With some overtime work by the field crew and a slight drop off in the rate of requests, we have been able to ‘catch up’ with treatments in almost all the towns. Basin treatments continue in all municipalities. Very few larvicide requests are being initiated at this time. Some of the locations are treated for mosquito larvae but most are either dry or have no larvae.

Contact

144 Production Rd, Suite C

Walpole, MA 02081

Office: (781) 762-3681
Fax: (781) 769-6436